Sometimes, the Celtics have a fluke loss you have to dismiss. But this wasn’t that, and it has me worrying about cracks in the supposedly-impenitrable armor

An uncharacteristically poor defensive night cost the Boston Celtics during their Christmas Day loss to the Philadelphia 76ers. Joe Mazzulla's team has been inconsistent on the defensive side of the floor all season despite consistently rising defensive rating rankings.

But Maxey zipped past Pritchard and found a clear lane to the basket, where he put in an off-balance layup just before time expired. The play all but finished off the Celtics in this 118-114 loss, and it was an example of the uncharacteristic missteps that doomed them.